With respect to prior arrangements of chain conveyors supporting products throughout multiple tiers within designated volumes of controlled atmospheres, the following prior United States patents are referred to:
In U.S. Pat. No. 3,243,032, issued in 1966, Louis J. Chambon disclosed his apparatus for conveying products throughout different levels. Continuous independent chain conveyors are positioned at each level. Trays are positioned in receivers attached to the chains and are then transferred, between conveyors, down to the next lower independent chain conveyor, using transfer wheels, as the trays remain level to support the product.
In U.S. Pat. No. 2,254,420, issued in 1941, Everett Cleveland disclosed his refrigerating apparatus in which his conveyor chains carry pivotally suspended baskets that in turn hold the product.
In U.S. Pat. No. 3,173,276, issued in 1965, Walter H. Martin disclosed his endless conveyor type freezer for conveying products throughout different levels. Trays are pivotally suspended below dual continuous chains of the conveyor. Refrigerating air flows are circulated transversely to the direction of the conveyor.
In U.S. Pat. No. 3,857,252, issued in 1974, Edward M. Wight disclosed his food product freezing apparatus for conveying products through a controlled temperature volume. A continuous roller chain carries individual plates which are individually and separately mounted in series on the side of this chain. The continuous roller chain moves down an incline, turns around a sprocket and continues moving down another incline, thus repeating this motion throughout the controlled temperature volume. The refrigerating airflow is circulated transversely to the direction of the continuous roller chain.
In U.S. Pat. No. 1,847,956, issued in 1932, Albert Giger disclosed his method of sharp freezing foodstuffs and the means therefor. The foodstuffs are placed in a plurality of shallow covered pans. Lugs on the pans are secured to transverse rods which are in turn secured to spaced conveyor chains. Tracks guide both the moving chains and pans through two processing levels. The brine refrigerant is applied transversely to the motion of the conveyor.
In U.S. Pat. No. 2,267,789, issued in 1941, Chester J. Conn disclosed his apparatus for freezing food products. During part of the conveyor travel the food products were in molds which were secured at each end to a continuous chain necessitating their being turned upside down at the ends of the conveyor. Such motion of the molds was utilized to unload the food products for further processing on another conveyor.
In U.S. Pat. No. 1,795,330, issued in 1931, Alexander Cooke disclosed his freezing apparatus operating essentially on one overall level. Carriers pivotally attached directly to an endless, one level conveyor transported the food products.
In U.S. Pat. No. 3,224,562, issued in 1965, Peter J. Bailey disclosed his conveyor system utilizing continuous spaced chains which raised and lowered containers removably hooked over cross bars, in turn secured to the chains.
In U.S. Pat. No. 2,723,645, issued in 1955, Orlando Garapolo disclosed his apparatus to provide meat with a surface glaze of ice. Spaced continuous conveyor chains carried permanently secured paddles which pushed the meat products through the glazing liquid.
In U.S. Pat. No. 2,923,138, issued in 1960, Wilbur Rollins disclosed his quick freezing apparatus, utilizing vertical layers of independent conveyors provided with foraminous wire mesh belts. The products are dropped from one level to another level. Refrigerating airflows are applied transversely to the motion of the conveyor.